Celtics coach Brad Stevens is trying to fire up his team for the playoffs. (Bob DeChiara/USA Today Sports)

For all the fret and worry over playoff scenarios, there’s one variable Brad Stevens is counting on: Togetherness.

It’s what the Celtics coach felt was missing the most on Monday night in the 114-100 loss to Charlotte at TD Garden. And it’s exactly what needs to be on display not only in the season finale against Miami but heading into the playoffs.

“I think no matter what, obviously we could win and not finish with home-court advantage,” Stevens said before Wednesday’s game with Miami. “We could win and finish with home-court advantage. I think the biggest thing is getting back to playing with the aggression and the spirit that we’ve played with in the past that has got us to this point. We didn’t play with that on Monday, so that’s really been my focus. All of these scenarios and that stuff, I can’t keep up with it.”

Stevens was still able to joke about Monday’s loss.

“When I was 17, I went and visited one of those people that tell you what you’re going to do with your life and they said you’re going to be an actuary or a basketball coach and I chose coaching,” Stevens said. “It’s probably a good thing because those numbers were spinning in my head when I look at them for five minutes.”

An actuary is defined on a Google search as “a business professional who analyzes the financial consequences of risk.” They use mathematics, statistics, and financial theory to study uncertain future events, especially those of concern to insurance and pension programs.

“I guess on Monday night I was thinking, man, there are probably a lot of people thinking he’d be better off being an actuary. I guess time will tell.”

Thanks to the number-crunching of Ben Rohrbach, we now know all the first-round possibilities for the Celtics in the playoffs that begin this weekend. The question is: What matchup might favor the Celtics and which matchup might give the Celtics the best path through the East? Is it too early to start thinking about avoiding either Toronto or Cleveland in the second round? That’s a question for later. But for now, who do you want to see the Celtics face in the opening round?

And if the Celtics drop to 9-10 in their final 19 games with a loss to the Heat on Wednesday night, dropping a third straight game to a potential playoff opponent with seeding on the line — not exactly a ringing endorsement of their chances in the playoffs, should that happen — they will:

a) visit Atlanta as No. 5 seed if Charlotte loses to Orlando.

b) visit Miami as No. 6 seed if Charlotte beats Orlando.

Confused enough? Me too. Welcome to the East behind Cleveland and Toronto. Just print this out, laminate it and keep it in your back pocket — like Jim Nantz and his burnt toast requirements:

The Celtics are ready to put on a playoff show for the likes of Patriots players Malcolm Butler (left) and Jamie Collins at TD Garden. (Bob DeChiara/USA Today Sports)

WALTHAM — This has been an odd year for the Celtics on their home court.

They started off 9-10 on the parquet. They suffered humiliating losses to the likes of the Lakers and Brooklyn back-to-back to open the new calendar year.

Then they went on a 14-game win streak, the longest in the 20-year history of TD Garden. They fell back to earth with a thud when they lost at home to schizophrenic Rockets, which preceded a blowout loss to Kevin Durant and the Thunder, a game they trailed by 30 at one point. The rebounded with four straight at home before losing a stinker Monday night to Charlotte, inexplicably getting outscored 39-13 in the third quarter.

All of this leads to one simple question: Will home court, if they earn it Wednesday night against the Heat, really be a factor for the Celtics when the playoffs start this weekend?

“So I’m not going to concern myself with things I can’t control, again,” coach Brad Stevens said in a classic, pleasant-sounding misdirection of a reply. “Hey, I think no matter what, in the playoffs, you can’t be a dud on the road and expect to win a playoff series. And you can’t be good but inconsistent at home and expect to win a playoff series. You just have to play well in the games that you have.

“Again, these guys, our team, as bitter a taste as we may feel from last night, has put ourselves in a great position all year with their play. These guys have really done a lot of good things. And we’ll look forward to playing whoever we play, wherever we play, when that time comes.”

The Celtics coach had enough on his plate Tuesday before practice digesting what exactly went wrong Monday night and trying to install changes in film and practice to make sure they don’t have a repeat on Wednesday night against Miami in the regular-season finale at TD Garden.

In short, if the 47-34 Celtics win, they wrap up the No. 4 seed and home-court advantage, barring a three-way tie with Miami and Atlanta. If the Heat lose to the Pistons on Tuesday night, that possibility is out the door since the Celtics would pass Miami in the standings with a win and finish No. 4.

If the Celtics lose, they are staring at a No. 5 or 6 seed.

“I think my level of concern or the amount of thoughts that are going through my head are probably the same regardless of the outcome,” Stevens said Tuesday. “I’m interested to see how we respond. This has been a good group as far as responding goes.”

And the playoffs?

“I’m interested to see how we respond to last night’s game today,” Stevens said before Tuesday’s practice. “Then, certainly [Wednesday]. Then, hey, no matter how this stuff all shakes itself out, which, somebody just put on my desk all the scenarios and I said, ‘Would you mind throwing that away?’ Like, it’s a headache to even try to figure out. We’re playing the three teams that we may play in the last three games. I thought we learned a lot of things that we can do well against Atlanta that maybe we haven’t done as well in the past.

“I thought last night we just got killed in that eight-minute stretch and we can take from that. We’ll see how we play tomorrow. Certainly, you’ve got to focus on the things that you can control, and that’s going to continue to stay the same.”

WALTHAM — There’s no one more explosive on the Celtics than Isaiah Thomas.

When that is controlled and confined to the scoring column, the Celtics, as the Warriors found out, can beat anyone in the NBA.

When it spins out of control as it did Monday night, the Celtics look helpless.

Part of what drew Danny Ainge to Thomas is exactly what he was as a player in the 1980s and ’90s. Thomas is a fierce competitor who loves to score and lead his team.

He can’t do that when he’s on the bench, frustrated and raising his hands at officials when calls don’t go his way. Brad Stevens saw the other side Monday and decided to bench Thomas after the guard picked up a technical with 3:55 left in the third quarter.

“Yeah, listen, you can’t do that. That’ll catch up with you,” Stevens said before Tuesday’s practice. “Those are things that you can talk about until you’re blue in the face, but you have to make sure you move on to the next play regardless. If you don’t, then that story tells itself. And you get burned by those things.”

After consecutive losses to playoff teams on Saturday and Monday, there is a little doubt creeping into the minds of Celtics fans.

Are the Celtics the team that beat Golden State and Cleveland on the road and posted a 47-32 record in their first 79 games? Or are they the team that has been exposed in the second half in Atlanta and the entirety of their humiliating loss to the Hornets on Monday night at home?

Avery Bradley said after Saturday’s game in Atlanta that the Celtics looked at times to be a team fighting itself and playing tight. After Monday’s 114-100 loss to Charlotte at TD Garden, Bradley laid it out on the line for a team that was outscored 39-13 in the second quarter and blown out of its own building.

“All the credit to them. We just have to prepare and try to fix all the mistakes we had,” Bradley said. “I know the coach said it. I’m pretty sure everybody else is going to say it. We just have to try to fix all the small things that we did [wrong] because in the playoffs, if we make these same mistakes, we might lose by 40.”